An array plate is also called a microtiter plate, microplate, or microwell plate. Array plates are typically used to hold respective liquid droplets separately for biological and/or chemical reaction. For example, a well-type array plate includes a plurality of wells so that each liquid droplet or each sample may be dispensed into a separate well for further processing. Typically, the number of wells is selected from 6, 24, 96, 384, 1536, 3456, and 9600.
Alternatively, hydrophobic material-coated slides have been used for holding larger volumes of droplets on a microscope slide surface. For example, the PTFE matrix is patterned on a glass slide (e.g., a microscope slide) so that the PTFE matrix covers portions of the glass microscope slide and the remaining portions of the glass microscope slide are not covered by the PTFE matrix. The PTFE matrix has hydrophobic characteristics and the portions of the glass microscope slide that are not covered by the PTFE matrix have hydrophilic characteristics. Aqueous solutions that include samples (e.g., cells) are typically placed on hydrophilic areas of the slide.
Samples (e.g., cells) are frequently washed. Washing typically involves adding a wash solution to a sample solution, including samples (e.g., cells), on the slide and removing the mixture of the wash solution and the sample solution. However, certain cells (e.g., suspension cells, non-adherent cells, and weakly adherent cells) do not strongly adhere to the slide. Thus, during removal of the mixture, cells may be removed along with the mixture, thereby reducing the number of cells that remain on the hydrophilic area of the slide after the washing. Because a reliability of cell-based reactions typically requires a sufficient number of cells, the loss of cells during washing negatively affects cell-based reactions.